The present disclosure relates generally to the field of signal detection.
Various communications systems include components intended to detect the presence of wireless communication signals (e.g., radio frequency, or RF, signals). Such communications systems may be applied in defense (e.g., military communications systems such as electronic warfare systems), commercial (e.g., cellular communications), residential (e.g., wireless home networks), and other realms. For example, in asymmetrical military operations, troops face new RF threats every day that can put them in harms way. In such operations, accurate detection of signals may be an important step in ensuring the safety of troops and the success of operations.
Signal detectors may include energy-based signal detectors and matched filter signal detectors. Energy-based signal detectors may differentiate between actual signals and background noise based on an energy level (e.g., a spectral energy level) of received signals. Energy-based signal detectors often require knowledge of background noise to determine a threshold energy level used to determine the presence of a signal. In order to obtain this knowledge, energy-based signal detectors may need to monitor background noise for an extended period of time. Matched filter based detectors may be optimal if all of the signal parameters and noise statistics associated with signals being received are known a priori. It is not practical to obtain a priori knowledge of all relevant signal parameters and noise statistics for many systems. Further, such knowledge is unavailable for new and previously unknown signals (e.g., new threats). Both energy-based signal detectors and matched filter signal detectors are typically limited to detecting a single signal at a time. Accordingly, such systems are incapable of handling detection of multiple threats that are present at the same time. Thus, there is a need for a computationally, inexpensive, real time signal detector that can detect signals present in unknown noise. Further, there is a need for a system for and a method of detecting multiple signals simultaneously irrespective of bandwidth and center frequencies.